JP4498298B2 - Wireless receiver - Google Patents

Description

  The present invention relates to a spatial multiplexing transmission wireless receiver that transmits and receives signals simultaneously using a plurality of transmitting antennas and a plurality of receiving antennas.

  As a technique for speeding up wireless communication, a technique has been proposed in which transmission signals are distributed to a plurality of radio devices and signals are simultaneously transmitted from a plurality of transmission antennas using the same frequency (for example, see Non-Patent Document 1). ). In this method, since signals transmitted from each antenna are received through different propagation paths, the receiving terminal receives signals using a plurality of receiving antennas, and signals transmitted simultaneously using the received signals. By separating the signals, the signal can be decoded. As a result, the transmission speed can be increased according to the number of multiplexed signals without increasing the frequency bandwidth used for communication. Therefore, according to this method, the frequency utilization efficiency can be increased and the throughput can be improved.

  On the other hand, in an environment where signals with different propagation delay times between transmission and reception arrive in a multipath propagation path, waveform distortion due to intersymbol interference is a major factor that degrades communication quality. In such an environment, the Orthogonal Frequency Division Multiplexing (hereinafter referred to as OFDM) method is a method that can compensate for waveform distortion caused by intersymbol interference even when signals having different propagation delay times are received. Known as.

The OFDM transmission system uses orthogonal subcarriers called multiple subcarriers. Therefore, in the environment where signals with different propagation delay times arrive, the propagation path response differs for each subcarrier. When the method proposed in 1 is applied, it is necessary to separate a multiplexed signal for each subcarrier. Therefore, since high-speed processing is required to realize high-speed transmission in real time, implementation with software is difficult, and implementation with hardware is necessary.
A. Paulraj, R. Nabar, and D. Gore, Introduction to Space-Time Wireless Communications, Cambridge University Press, UK, 2003, pp. 6-10.

However, if the device is configured with hardware, the expandability of functions is significantly reduced. For example, when using a terminal that can receive two multiplexed signals so that two multiplexed signals can be received, the signal can be separated when three or more signals are multiplexed. Therefore, transmission of information becomes impossible. Therefore, when higher-speed transmission is required and the number of signals to be multiplexed increases, this terminal cannot receive signals, so the terminal must be completely remade.
Also, if the device is configured in anticipation of an increase in the number of signals that are multiplexed in advance, if two multiplexed signals are sufficient, it becomes overspec, the size of the device becomes larger than necessary, and power consumption There is a problem that becomes large.
As described above, the conventional radio receiving apparatus has a problem of poor function expandability. In addition, there is a problem that the device becomes enlarged if it is made to have expandability, the chip area increases, the power consumption increases, and the wiring becomes complicated.

  In view of the above problems, an object of the present invention is to provide a radio receiving apparatus having function expandability without causing unnecessary expansion of the apparatus in a system for multiplexing and transmitting a plurality of OFDM signals simultaneously. And

  In order to solve the above-described problem, a wireless reception device of the present invention includes a plurality of antennas that receive multiplexed signals, a plurality of wireless units that are connected to the plurality of antennas in a one-to-one relationship, and the plurality of wireless devices. A plurality of analog-to-digital converters which are connected to the units in a one-to-one relationship and convert analog signals into digital signals, and timing calculation means for calculating the timing of applying Fourier transform to each of the digital signals based on each of the digital signals And an error between the frequency of the transmitter of the received analog signal and the frequency of the radio unit based on the plurality of digital signals that are output from the analog-digital conversion unit, connected to the plurality of analog-digital conversion units The first generation means for generating the same number of digital signals as the plurality of radio units, in which the frequency offset amount is corrected, and the plurality of radio units has a one-to-one correspondence. A plurality of Fourier transform units that apply a Fourier transform to the plurality of generated digital signals, a propagation path estimation means that estimates a propagation path response based on the plurality of Fourier transformed digital signals, A second generation unit configured to correct an error that has not been corrected by the first generation unit based on the plurality of Fourier-transformed digital signals, and to generate the same number of digital signals as the plurality of radio units; and the propagation path A weight calculating unit for calculating a plurality of weights for separating the multiplexed signal based on a response; a first interface connected to another module; the propagation path estimating unit; and the weight calculating unit. A state in which the propagation path estimation means and the weight calculation means are connected, or the propagation path estimation means and the first interface A first switch that switches to any one of the connection states, a separate demodulator that separates and demodulates the multiplexed signal received from the second generator based on the plurality of weights, and the other A second interface connected to the module, and a state in which the second generation unit and the separation / demodulation unit are connected to each other, or the second generation unit Switching to one of the states in which the first and second interfaces are connected, the same number of second switches as the plurality of radio units, decoding means for decoding each of the separated and demodulated signals, and control of switching of each switch A first module and a second module, each comprising a switch control means, wherein the switch control means of the first module comprises the first module The first switch of the first module is controlled so as to connect the propagation path estimation unit of one module and the weight calculation unit of the first module, and the second generation unit of the first module and the first module are separated. The second switch of the first module is controlled so as to be connected to the demodulating means, and the weight calculating means of the first module is further connected via the first interface of the second module. And controlling the first switch of the second module so as to calculate based on the propagation path response from the propagation path estimation means of the second module, and the separation and demodulation means of the first module further includes the second module. Controlling the second switch of the second module to receive the multiplexed signal received from the second generating means; The one-module weight calculation means calculates the number of weights corresponding to the plurality of signals received by the plurality of antennas of the first module and the second module, and the first module separation / demodulation means includes the first module Each of the signals received by the plurality of antennas of the module and the second module is combined to separate the multiplexed signals.

  According to the wireless reception apparatus of the present invention, in a system that multiplexes and transmits a plurality of OFDM signals simultaneously, unnecessary expansion of the apparatus does not occur and the function can be expanded.

Hereinafter, a radio reception apparatus according to an embodiment of the present invention will be described in detail with reference to the drawings.
(First embodiment)
A radio reception apparatus according to a first embodiment of the present invention will be described with reference to FIG. FIG. 1 shows a configuration of a receiving apparatus according to the first embodiment.
The wireless receiving apparatus of the present embodiment includes two modules, a receiving module 1100 and a receiving module 2150. Each receiving module includes two receiving antennas, radio units 101, 102, 151, 152, A / D converters 103, 104, 153, 154, timing synchronization units 105, 155, automatic frequency controllers 106, 156, FFT 107, 108, 157, 158, propagation path estimation units 109, 159, phase correctors 110, 160, MIMO reception weight calculation units 111, 161, MIMO demodulators 112, 162, decoders 113, 163, control units 114, 164 , Switches 116, 117, 118, 119, 166, 167, 168, 169, and switch controllers 115, 165.
In addition, each reception module includes a propagation path response estimated by the propagation path estimation units 109 and 159, a signal after phase correction by the phase correctors 110 and 160, and a control signal generated from the received header signal. , To the outside. Further, each receiving module has an interface for inputting a propagation path response estimated by an external receiving module, a signal whose phase has been corrected by the external receiving module, and a control signal. In the following, the same parts as those already described are designated by the same reference numerals and the description thereof is omitted.

  Radio units 101, 102, 151, and 152 convert the received signal received by the antenna into a baseband signal. The A / D converters 103, 104, 153, and 154 convert analog baseband signals into digital signals. The timing synchronization units 105 and 155 obtain timing (synchronization position) at which FFT conversion is applied to the signal output from the A / D converter. Automatic frequency controllers 106 and 156 correct for local frequency errors in the receiver and transmitter. The FFTs 107, 108, 157, and 158 convert time domain signals into frequency domain signals. The propagation path estimation units 109 and 159 estimate the propagation path response necessary for correcting the waveform distortion due to the propagation path, based on the frequency domain signal. Details of the timing synchronization units 105 and 155, the automatic frequency controllers 106 and 156, and the FFTs 107, 108, 157, and 158 will be described later with reference to FIG. Details of the propagation path estimation units 109 and 159 will be described later with reference to FIG.

  The phase correctors 110 and 160 correct the phase error of the signals output from the FFTs 107, 108, 157 and 158. MIMO reception weight calculation sections 111 and 161 calculate weights necessary for separating multiplexed signals based on the propagation path response. MIMO demodulators 112 and 162 demultiplex and demultiplex the multiplexed signals. Decoders 113 and 163 decode the signals demodulated by MIMO demodulators 112 and 162. The control units 114 and 164 generate a control signal for determining a reception operation from the received header signal. The control units 114 and 164 control whether or not to stop the operation of each unit in each module. Switches 116, 117, 118, 119, 166, 167, 168, and 169 change the connection destination and change the signal flow. The switch control units 115 and 165 generate control signals for switching the switches 116, 117, 118, 119, 166, 167, 168, and 169, and switch 116, 117, 118, 119, 166, 167, 168, 169. Output to.

  Each reception module configured as described above can receive a signal transmitted by multiplexing two signals by using them individually without being connected to each other. These two receiving modules are connected as shown in FIG. 1, and four multiplexed signals can be received. The operation of the wireless reception device will be described in detail below.

First, the multiplexed and transmitted signal is received using each antenna of the reception module 1 and the reception module 2. Here, any antenna may be used regardless of whether it is a directional antenna or an omnidirectional antenna as long as it can receive a signal in a desired frequency band. To do.
Next, RF (Radio Frequency) signals received by the respective antennas of the respective reception modules are converted into baseband signals by the radio units 101, 102, 151, 152 connected to the respective antennas. Here, the radio unit in the embodiment of the present invention is a general radio unit including a frequency converter, a filter, a variable gain amplifier, and the like, and does not limit the configuration of the radio unit in the embodiment. Since it is not an essential device part, details are omitted. The A / D converters 103, 104, 153, and 154 convert the signals converted into baseband signals into digital signals.

  Next, the timing synchronization units 105 and 155 obtain timings at which each FFT module applies the FFT window using the signal converted into the digital signal. In general, in wireless communication, a known signal for equalizing a signal distorted by a propagation path is transmitted by synchronizing the timing and frequency using a frame head. The timing synchronization units 105 and 155 can obtain the synchronization timing by using such a known signal.

  An example of a frame format having this frame head will be described with reference to FIG. The frame format shown in FIG. 2 is based on IEEE802.11a, which is a wireless LAN standard. As shown in FIG. 2, sp that is repeatedly transmitted 10 times at the head of the frame is called a short preamble, and includes timing synchronization, frequency synchronization, and gain for AGC (auto gain control). Has been transmitted to seek.

  Timing synchronization sections 105 and 155 prepare a signal of the same series as the known signal to be transmitted as a reference signal, and obtain a cross-correlation value between the received signal and the reference signal. When the timing at which the known signal arrives and the reference signal for obtaining the cross-correlation are synchronized, the cross-correlation value exhibits a high peak. Conversely, if the synchronization is not achieved, the cross-correlation value exhibits a low value. Therefore, the timing at which the signal arrives can be obtained by detecting the peak position of the cross-correlation value.

  Further, when the same signal is repeatedly transmitted as a known signal as in IEEE 802.11a shown in FIG. 2, the synchronization timing can be obtained from the autocorrelation value of the received signal without using the reference signal. When the received signal is shifted by the signal length of sp, the signal having the complex conjugate is multiplied by the original signal, and the moving average for the signal length of sp is obtained, the time during which sp is repeatedly transmitted is shifted. Since the original signal becomes the same signal, a high autocorrelation value is shown. On the other hand, when the reception of sp ends and the time when LP is received is reached, the periodicity is lost and the autocorrelation value decreases. Therefore, sp is repeatedly transmitted during the time when the autocorrelation value is high, and the timing when the LP arrives can be estimated by obtaining the time when the autocorrelation value is low.

As described above, the method of transmitting a known signal and using the cross-correlation between the reference signal and the received signal and the autocorrelation of the received signal as a method for estimating the synchronization timing has been described. However, the synchronization timing estimation method in the present invention is not limited to the above two methods. Any other method may be used as long as the synchronization timing can be estimated.
On the other hand, the automatic frequency controllers 106 and 156 correct the frequency error between the transmitter and the receiver using the signal converted into the digital signal by the A / D converter described above. In general, it is difficult to precisely match the local frequency generated in the radio unit with a desired frequency, and some errors are included. As a result, the frequency offset generated between the local frequencies generated by the transmitter and the receiver causes the transmission quality to deteriorate. When such deterioration occurs, in the case of the OFDM signal assumed in the embodiment of the present invention, the orthogonality between the subcarriers is lost, and the signals of the subcarriers interfere with each other. Further, since phase rotation due to frequency offset occurs with time, there is also a problem that the phase of the desired signal rotates.

In order to solve such a problem, the automatic frequency controllers 106 and 156 estimate the amount of frequency offset generated between the transmitter and the receiver and correct the frequency. As a technique for estimating the frequency offset amount, for example, the following (1) technique using sp, (2) technique using LP, and (3) technique using GI are listed.
(1) When a signal is transmitted in the frame format as shown in FIG. 2, a specific example of estimating the frequency offset amount is a method using sp. As shown in FIG. 2, since the same signal is transmitted for 10 consecutive symbols of sp, assuming that the noise component can be ignored, the same signal is continuously received when no frequency offset occurs. . On the other hand, when a frequency offset has occurred, a signal having a phase rotation corresponding to the length of sp is received as the signal after one symbol. Therefore, the frequency offset amount can be estimated by obtaining the phase difference of the signal after one symbol.

However, since the received signal includes noise in addition to the frequency offset, it is necessary to remove the influence of noise. When 10 symbols are transmitted as shown in FIG. 2, the influence of noise can be removed by calculating the average using an arbitrary number of samples of the 10 symbols. That is, the frequency offset can be estimated using the received signal r (n) as in the following equation.

However, T is the number of samples of sp of one symbol, * is a complex conjugate, n is an integer of 1 or more, and arg (•) is an argument of •. Further, equation (1) indicates that the average is obtained using b samples from the a sample in the sp interval, and the average can be obtained by arbitrarily setting the number of samples of 10 symbols of sp. it can. M is an integer of 1 or more, and represents that the phase difference from the received signal after m symbols is measured, and is arbitrarily set in consideration of the number of symbols of sp and the number of samples for obtaining the average. . In general, as the number of samples to be averaged is increased, the influence of noise is reduced and the estimation accuracy can be improved. However, if the number of samples is increased, a processing delay is generated accordingly. Therefore, the number of samples to be averaged is determined in consideration of estimation accuracy and processing delay.
In addition, since each receiving module receives signals with two antennas, more accurate estimation can be performed by obtaining an average using signals received by the respective antennas.

  (2) The frequency offset estimation described above can be applied to signals other than sp as long as it is a periodic signal. In the format shown in FIG. 2, it can be seen that LPs are transmitted continuously for two symbols. Since the timing of receiving the LP can be estimated from the result of the timing synchronization described above, the frequency offset amount can be estimated by obtaining the phase difference between the first symbol and the second symbol by averaging the arbitrary number of samples of the LP. Similarly to the estimation using sp, the estimation using LP can improve the estimation accuracy by increasing the number of samples, and the accuracy can be further improved by averaging the signals received by the respective receiving antennas. . On the other hand, if the number of samples to be averaged is increased, the problem that the processing delay increases occurs as in the case of using sp.

  (3) In addition to estimation using these known signals, estimation can also be performed using a GI (Guard Interval) added to the OFDM signal. Since GI is obtained by copying several samples at the end of the OFDM symbol at the beginning, the amount of frequency offset can be estimated in the same manner as when using sp or LP by obtaining the phase difference between GI and the end of the symbol.

As described above, the method of estimating the frequency offset amount using sp, LP, and GI has been described using the format of FIG. 2 as an example, but the frequency offset estimation method in the embodiment of the present invention is not limited to the above three methods. Absent. As long as the frequency offset amount can be estimated, other methods may be used for estimation.
Using the frequency offset amount f _off thus estimated, the received signal r (n) is multiplied by the inverse characteristic of the offset amount as follows.

However, _{T S} represents the sampling interval of the ^signal, j 2 = ^-1, is π is the circular constant. Thus, the frequency offset can be compensated by multiplying the inverse characteristic of the offset amount.

  The FFTs 107, 108, 157, and 158 perform a discrete Fourier transform on the signal after the frequency offset amount is compensated as described above with reference to the synchronization position obtained by the above-described timing synchronization, and perform a frequency domain signal. Convert to At this time, the discrete Fourier transform may use DFT (Discrete Fourier Transform) or FFT (Fast Fourier Transform). Any method may be used as long as the signal in the time domain can be converted into the frequency domain.

In order to demodulate the signal in the frequency domain output by the FFT, it is necessary to know what kind of distortion the transmission signal has received by radio wave propagation, and the propagation path estimation units 109 and 159 estimate the distortion. In order to estimate this distortion, a known signal for channel response estimation is generally transmitted before data is transmitted. In the case of the IEEE802.11a format shown in FIG. 2, LP corresponds to the signal. Note that the propagation path estimation units 109 and 159 need to estimate the propagation path response for each multiplexed signal when a plurality of signals are transmitted simultaneously.
There are various methods for estimating a channel response using a known signal. Typical techniques include a technique of multiplying a received signal in the frequency domain by a generalized inverse matrix generated from a known signal, a technique of estimating an impulse response in the time domain, and converting it to the frequency domain. Note that any method may be used for the channel response estimation unit in the embodiment of the present invention. Any method other than the above two methods may be used. Any method may be used as long as the channel response for each signal to be multiplexed can be estimated.

  Next, the phase correctors 110 and 160 compensate for the frequency offset and phase noise remaining due to the estimation error in the automatic frequency controllers 106 and 156. Generally, in order to correct such distortion in the OFDM scheme, data is not transmitted on some subcarriers, but a known pilot signal is transmitted. Using this signal, the phase is corrected by the phase corrector of each receiving module in FIG.

As a method for estimating the amount of phase change due to the frequency offset remaining due to the estimation error and the phase noise, it is obtained from the phase change obtained by comparing the received signal of the pilot signal with the received signal of the pilot signal one symbol before. A method for estimating the amount of phase change can be mentioned. Further, since there are pilot signal reception signals of (the number of pilot subcarriers) × (the number of reception antennas), it is possible to estimate the amount of phase change to be obtained by obtaining an average of them as in the following equation.

Here, x indicates the number assigned to the receiving antenna, p indicates the number assigned to the pilot signal, and f indicates the frequency of the received signal. Also, r _x ^(fp) (n) represents the signal of the fp-th subcarrier of the n-th OFDM symbol received by the x-th receiving antenna.

  Since the phase change amount (phase error) obtained as a result of the above is a phase error for one symbol, the phase correctors 110 and 160 calculate the accumulated phase difference from the data head and reverse the obtained phase difference. Phase correction can be performed by multiplying the received signal by the characteristic.

  As another phase error estimation method, a replica of a received signal is generated using the above-described propagation path response value and pilot signal, and a replica generated instead of the received signal one symbol before in Equation (3) is used. A method for estimating the phase difference can be mentioned. In this method, unlike the method using the received signal one symbol before, the accumulated phase difference is obtained. Therefore, the phase error is reduced by multiplying the received signal by the inverse characteristic of the phase difference obtained in Equation (3). Can be compensated.

  As described above, the two methods of using the received signal of the previous symbol and the method using the replica signal have been described as the method of estimating the phase error in the phase correctors 110 and 160. The phase correction in the embodiment of the present invention However, the phase error estimation method in the detector is not limited to these methods. Any method may be used as long as the phase error can be estimated.

Next, separation of spatially multiplexed signals performed by the MIMO demodulators 112 and 162 will be described. The radio reception apparatus according to the embodiment of the present invention is an apparatus for receiving signals transmitted simultaneously from a plurality of antennas, and is received in a state in which the plurality of signals are wirelessly mixed. Here, r _i ^(k) (n) is the signal of the kth subcarrier of the nth OFDM symbol received by the ith receive antenna, and the nth OFDM symbol of the nth OFDM symbol transmitted from the jth transmit antenna. If the signal of the kth subcarrier is s _j ^(k) (n) and the propagation path response between the jth transmission antenna and the ith reception antenna in the kth subcarrier is h _{i, j} ^(k). The relationship of the following formula is satisfied.

Here, n _i ^(k) (n) represents noise added to the k th subcarrier in the n th OFDM symbol in the i th receive antenna. Furthermore, when the signals received by all the receiving antennas are expressed as vectors using the signals transmitted from all the transmitting antennas, they can be expressed as follows.

  As described above, the signals received from each receiving antenna are mixed with signals transmitted from all transmitting antennas, and in order to demodulate and decode the signals transmitted from each antenna, The transmission signal needs to be separated.

The above separation is performed for each OFDM subcarrier, and multiplexed signals are separated by weighted synthesis of the signals received by the respective antennas based on the above-described propagation path response estimation values.

Here, r _k (n) is a reception vector whose element is the signal of the k-th subcarrier of the n-th OFDM symbol received by each reception antenna, and W _k is a weight for weighted synthesis of each reception antenna. The matrix is a 4 × 4 order matrix when the number of multiplexed signals is 4 and the number of receiving antennas is 4. T represents transposition. The weight is calculated by the MIMO reception weight calculation units 111 and 161.

As described above, as a typical technique for obtaining the weight for separating each signal from the propagation path estimation value, there is a technique for optimizing the weight based on the Zero-Forcing standard or the MMSE (Minimum Mean Square Error) standard. The weight of the Zero-Forcing criterion is expressed as follows using the channel response matrix H _k .

The weight of the MMSE standard is expressed as follows using a channel response matrix.

  However, some other weight determination methods are conceivable, and the weight determination method in the embodiment of the present invention is not limited to these two methods. Any method may be used as long as the multiplexed signal can be separated.

  It can be seen that the weighted combining weights for the multiple signal separation described above are calculated using the propagation path response estimation values at all receiving antennas of each multiplexed signal, regardless of the weight determination method. Therefore, in the case of a configuration in which demodulation is performed using signals received by a plurality of receiving modules as in the embodiment of the present invention, it is necessary to obtain the above-described weight using propagation path response values estimated by all the receiving modules. is there.

  FIG. 3 shows a conceptual diagram of a propagation path response matrix estimated by the propagation path estimation units 109 and 159 in each receiving module according to the present invention. As described above, when four multiplexed signals are received, it is necessary to estimate all 16 channel responses in FIG. In addition, each receiving module in the embodiment of the present invention is a module capable of demodulating two multiplexed signals transmitted by using two receiving antennas alone, and originally only the enclosed portion 301 in FIG. It is sufficient to estimate However, if the propagation path estimator is configured so as to estimate only this location, it is impossible to estimate all the propagation path responses even if two receiving modules are combined. Therefore, the propagation path response estimation unit of each receiving module according to the embodiment of the present invention is configured to be able to estimate 8 components of 2 rows and 4 columns as shown by a solid line enclosed portion 302 and a broken line enclosed portion 303 in FIG. .

  When the propagation path response estimated in this way is used by combining two reception modules as shown in FIG. 1, the propagation path response estimation value estimated by the reception module 2 150 is used as the MIMO of the reception module 1 100. The data is transmitted to the reception weight calculation unit 111. The propagation path estimation unit 109 is connected to the MIMO reception weight calculation unit 111 of the reception module 1, and the propagation path response estimation value is transmitted to the MIMO reception weight calculation unit 111.

  As a result, the propagation path response values of the signals received by all the receiving antennas of the receiving module 1 and the receiving module 2 are collected in the MIMO reception weight calculation unit 111, and the estimation result of all the propagation path responses shown in FIG. 3 is obtained. Thus, it is possible to calculate the weight for the multiple signal separation described above.

  Further, as will be described later, the receiving module 2 does not separate the multiplexed signals. Therefore, when two receiving modules are combined and applied as in the embodiment of the present invention, the MIMO receiving weight calculation of the receiving module 2 is performed. Power consumption can be reduced by stopping the clock supply to the unit 161 by the control unit 114 and stopping the operation.

  By applying the weight obtained as described above to the signal whose phase is corrected by the above-described phase corrector as shown in Expression (6), each signal can be separated.

  In the radio reception apparatus according to the embodiment of the present invention, demodulation is performed using signals received by a plurality of reception modules, and thus the signal received by the reception module 2 needs to be transmitted to the reception module 1. Therefore, when the receiving module 2 is used without being combined with the receiving module 1, it is connected to the MIMO demodulator 162 of the receiving module 2, but when it is applied with being combined with the receiving module 1, as shown in FIG. The switch 167 is switched by the switch control signal generated by the switch controller 165, and the signal phase-corrected by the phase corrector 160 of the receiving module 2 is connected to the receiving module 1 and transmitted to the MIMO demodulator 112 of the receiving module 1. . The above switch control signals are generated by the switch control unit 165 in the receiving module 2 in the example of FIG. 1, but the switch control signals 115 and 165 are not included in each receiving module, and a method of inputting a switch control signal from the outside may be used. Absent.

The signal whose phase has been corrected by the phase corrector 110 of the reception module 1 is directly connected to the MIMO demodulator 112 of the reception module 1 and, as a result, is received by the reception module 1 and the reception module 2 by the MIMO demodulator 112 of the reception module 1. Collected signals.
At this time, similarly to the MIMO reception weight calculation unit 161 of the reception module 2 described above, the MIMO demodulator 112 of the reception module 2 can also prevent power consumption by stopping the clock supply and stopping the operation.

  Using the multiplexed signal separation weight obtained as described above and the received signals obtained by the plurality of receiving modules, the multiplexed signal is separated in the MIMO demodulator 112 of the receiving module 1 and demodulated. .

  At this time, the output of the MIMO demodulator outputs a different value depending on the decoding method of the decoder to which the MIMO demodulator is connected. When the decoder is a hard decision decoder, the MIMO demodulator separates the multiplexed signal, determines the bit transmitted from the separated signal, and outputs a hard decision result of 0 or 1. On the other hand, when the decoder is a soft decision decoder, the MIMO demodulator determines the likelihood of the bit transmitted from the signal after the signal separation and the modulation point of the signal, and outputs a soft output.

  The signal output from the MIMO demodulator 162 of the reception module 1 is connected to the decoder 113 of the reception module 1. The decoder of the reception module 1 performs decoding using the input signal and outputs a decoding result of the transmitted signal. Here, when interleaving or puncturing is performed at the transmitting terminal, the decoder also performs deinterleaving or depuncturing processing.

In addition, various decoding methods such as Viterbi decoding, Max-Log-MAP decoding, and BCJR decoding can be cited as the decoding method. Any decoding method may be used in the embodiment of the present invention. Any method other than the above may be used, and either hard decision decoding or soft decision decoding may be used. Any method may be used as long as it can decode the encoding method applied at the time of transmission.
Similarly to the above-described MIMO reception weight calculation unit and MIMO demodulator, the decoder 163 of the reception module 2 can also stop the clock supply and prevent power consumption.

  FIG. 2 shows a system in which the communication system supports various modulation schemes, coding rates, data sizes, and signal multiplex numbers, and these schemes can be switched adaptively according to propagation path conditions. The above information is transmitted in advance like SIGNAL in the IEEE802.11a format. In the embodiment of the present invention, a control signal is generated based on the information received by the control unit 114 of the reception module 1 shown in FIG. 1, and a phase corrector, a propagation path estimation unit, a MIMO demodulator, a MIMO reception weight is generated. The operation of the calculation unit and the propagation path estimation unit is switched. At this time, since it is necessary to perform the same control for the receiving module 2, a similar control signal is transmitted from the receiving module 1 to the receiving module 2, and the receiving module 2 uses the control signal from its own control unit 164. Instead, the switch is switched so as to use a control signal input from the outside, and the control signal is input to each block of the reception module 2.

  In the example of FIG. 1, the generated control signal is transmitted from the reception module 1 to the reception module 2. However, as illustrated in FIG. 4, the result of the decoding of the information such as SIGNAL by the decoder 113 is transmitted via the switch 402. Even if the control units 401 and 451 generate control signals in the receiving module 1 and the receiving module 2, respectively, the same control signal is generated in the receiving module 2. Therefore, either configuration shown in FIGS. 1 and 4 may be used.

  As described above, according to the present embodiment, a plurality of individually operating reception modules can be combined and operated with their functions expanded, so that the number of separable signals can be increased. In addition, when the number of multiplexed signals is the same as when each receiving module is operated individually, the number of receiving antennas increases, so that the diversity gain increases, and the reception decoding accuracy can be improved. Furthermore, it is possible to prevent waste of power consumption by stopping the functions of the MIMO reception weight calculation unit, the MIMO demodulator, and the decoder of the reception module 2 that are no longer required to be used by combining the reception modules. In addition, since each receiving module in the embodiment of the present invention is a module that operates individually, it is also possible to use a single receiving module without expanding a plurality of receiving modules according to a user's request. It becomes simple.

(Second Embodiment)
A radio reception apparatus according to the second embodiment of the present invention will be described with reference to FIG.
The present embodiment also uses two receiving modules 500 and 550, and has an interface for outputting the channel response estimated by the channel estimation unit and the signal after phase correction by the phase corrector to the outside, Similar to the first embodiment, there is an interface for inputting the propagation path response estimated value estimated by the external receiving module and the signal phase-corrected by the external receiving module to the MIMO reception weight calculation unit and the MIMO demodulator. is there. This embodiment is different from the first embodiment in that each reception module has an interface for outputting the synchronization timing estimated by the timing synchronization unit to an external reception module and an interface for setting the synchronization timing from the external reception module. It is a point. As shown in FIG. 5, switches 501, 551 and interfaces associated with these switches are newly added.

  As described in the first embodiment, it is necessary to estimate the timing at which a signal arrives in wireless communication. In the first embodiment, each receiving module individually obtains the synchronization timing. However, since the difference in the timing of signal arrival between the receiving modules is not so large, it is necessary to estimate the synchronization timing by each of the two receiving modules. However, it is often sufficient to estimate with one receiving module.

  Therefore, in this embodiment, as shown in FIG. 5, the synchronization timing is estimated by the timing synchronization unit 155 of the reception module 2, and the obtained synchronization timing is received not only through the reception module 2 but also through the interface connecting the two. Also set as the synchronization timing. At this time, the timing synchronization unit 105 of the reception module 1 stops the operation by stopping the clock supply by the control unit 114. Thereby, unnecessary power consumption can be prevented. Other processes are the same as those in the first embodiment, and the function of the wireless reception device can be expanded using a plurality of reception modules as in the first embodiment.

  In FIG. 5, the synchronization timing estimated by the timing synchronization unit 155 of the reception module 2 is used. However, the synchronization timing estimated by the timing synchronization unit 105 of the reception module 1 can be set in each reception module. The control unit 164 can stop the operation of the timing synchronization unit 155 of the reception module 2 by stopping the supply of the clock.

  As described above, according to the present embodiment, in addition to the effects of the first embodiment, the reception module 2 estimates the synchronization timing, and the obtained synchronization timing can be used not only as the reception module 2 but also as the synchronization timing of the reception module 1. By setting, unnecessary power consumption can be prevented.

(Third embodiment)
A radio reception apparatus according to the third embodiment of the present invention will be described with reference to FIG.
In this embodiment, the same points as in the first embodiment use two receiving modules. The synchronization timing estimated by the timing synchronization unit, the channel response estimated by the channel estimation unit, and the phase corrector A point having an interface for outputting the signal after phase correction to the outside, a point having an interface for setting the synchronization timing based on the synchronization timing estimated by the external reception module, a propagation path response estimated value and an external reception module This is a point having an interface for inputting the phase-corrected signal to the MIMO reception weight calculation unit and the MIMO demodulator.

  This embodiment differs from the first embodiment in that each receiving module outputs an A / D converted signal to an external receiving module and an A / D converted signal is input from the external receiving module. It has an interface and estimates synchronization timing using signals received by a plurality of receiving modules. Therefore, the number of signals input to the timing synchronization units 601 and 651 is different from that in the first embodiment.

  As described in the first embodiment and the second embodiment, it is necessary to estimate the timing at which a signal arrives in wireless communication. In the first embodiment and the second embodiment, the synchronization timing is obtained using signals received individually by the respective receiving modules. However, as described in the second embodiment, the difference in timing at which signals arrive between the receiving modules is not so large. In addition, the method using the correlation as described in the first embodiment may not be able to accurately obtain the correlation value due to the influence of noise. In this case, the accuracy of the synchronization timing deteriorates due to the influence of noise. End up. Even if a method other than the above-described estimation method is used, the estimation accuracy may generally deteriorate due to the influence of noise.

Therefore, in the present embodiment, as shown in FIG. 6, the signal after A / D conversion of the receiving module 2 is transmitted to the receiving module 1, and the signals received by the timing synchronization unit 601 of the receiving module 1 by a plurality of receiving modules are used. To estimate the synchronization timing. Since the noise added to the reception signal of each reception module is considered to be uncorrelated, the influence of noise can be reduced by adding power to the correlation value obtained by each reception module. As a result, the obtained synchronization timing is set not only as the reception module 1 but also as the synchronization timing of the reception module 2 through an interface connecting the two. At this time, the control unit 164 stops the operation of the timing synchronization unit 651 by stopping the clock supply to the timing synchronization unit 651 of the reception module 2. Thereby, unnecessary power consumption can be prevented.
Other processes are the same as those in the first embodiment, and the function of the wireless reception device can be expanded using a plurality of reception modules as in the first embodiment.

  In FIG. 6, the synchronization timing estimated by the timing synchronization unit 601 of the reception module 1 is used. However, the synchronization timing estimated by the timing synchronization unit 651 of the reception module 2 can also be set in each reception module. The timing synchronization unit 601 of the receiving module 1 can stop the operation by stopping the supply of the clock.

  As described above, according to this embodiment, in addition to the effects of the first embodiment, the timing synchronization unit is operated using signals received by all the reception modules, so that the synchronization timing estimation accuracy can be improved. Further, the MIMO reception weight calculation unit, the MIMO demodulator, and the decoder of the reception module 2 that are no longer required to be used by combining the reception modules are deactivated, and the timing synchronization unit is operated only by one reception module. The waste of power consumption can be prevented by stopping the timing synchronizers of other receiving modules.

(Fourth embodiment)
A radio reception apparatus according to the fourth embodiment of the present invention will be described with reference to FIG.
In this embodiment, the same points as in the first embodiment use two receiving modules. The synchronization timing estimated by the timing synchronization unit, the channel response estimated by the channel estimation unit, and the phase corrector A point having an interface for outputting the signal after phase correction to the outside, a point having an interface for setting the synchronization timing based on the synchronization timing estimated by the external reception module, a propagation path response estimated value and an external reception module This is a point having an interface for inputting the phase-corrected signal to the MIMO reception weight calculation unit and the MIMO demodulator.

  This embodiment is different from the first embodiment in that each receiving module has an interface for outputting the frequency offset amount estimated by the automatic frequency controller to the external receiving module, and the frequency offset amount from the external receiving module. The frequency offset is compensated by the automatic frequency controllers 701 and 751, and each receiving module is multiplied by the inverse characteristic of the same frequency offset amount.

  As described in the first embodiment, in wireless communication, a local frequency error occurs between a transmitter and a receiver, and thus it is necessary to compensate for a frequency offset. At this time, when a clock is supplied from a common transmitter (not shown) to the receiving module 1 700 and the receiving module 2 750, the local frequencies generated by the receiving module 1 700 and the receiving module 2 750 are the same frequency. Therefore, it is desirable that the same signal is multiplied by the inverse characteristic of the frequency offset multiplied by the automatic frequency controllers 701 and 751.

  On the other hand, if the frequency offset amount is estimated by the method shown in the first embodiment, an estimation error occurs due to the influence of noise, and the frequency offset amount cannot be estimated strictly. Therefore, when the frequency offset amount is estimated individually in each receiving module as in the first to third embodiments, the frequency offset amount estimated in each receiving module is different, and the frequency that is different in each receiving module. An offset remains. As a result, it becomes difficult to separate the multiplexed signals in the MIMO demodulator, and there is a problem that the characteristics deteriorate.

Therefore, in this embodiment, the frequency offset amount is estimated using the automatic frequency controllers 701 and 751 of either one of the receiving modules, the estimated frequency offset amount is transmitted to the other receiving modules, and this offset amount is used. Compensates for frequency offset.
As a result, the amount of frequency offset remaining after compensating the frequency offset by the automatic frequency controller becomes the same in each receiving module, and signal separation can be performed by the MIMO demodulator.

  As described above, according to the present embodiment, in addition to the effects of the first embodiment, the frequency offset amount remaining in each reception module is the same, so that it is possible to prevent deterioration in signal separation of the MIMO demodulator.

(Fifth embodiment)
A radio reception apparatus according to the fifth embodiment of the present invention will be described with reference to FIG.
In this embodiment, the same points as in the first embodiment use two receiving modules, the channel response estimated by the channel estimation unit, the signal after the phase correction by the phase corrector, And an interface for inputting the propagation path response estimated value estimated by the external receiving module and the signal phase-corrected by the external receiving module to the MIMO reception weight calculation unit and the MIMO demodulator, respectively. It is a point which has.

  This embodiment differs from the first embodiment in that each receiving module outputs an A / D converted signal to an external receiving module and an A / D converted signal is input from the external receiving module. The frequency offset amount is estimated by automatic frequency controllers 801 and 851 using an interface and signals received by a plurality of receiving modules. Therefore, the number of signals input to the automatic frequency controllers 801 and 851 is different from that in the first embodiment.

  As described in the first embodiment and the fourth embodiment, in wireless communication, an error in local frequency occurs between the transmitter and the receiver, so it is necessary to compensate for the frequency offset. Further, as described above, there is a possibility that the frequency offset amount cannot be strictly estimated due to the influence of noise.

Therefore, in the present embodiment, the automatic frequency controllers 801 and 851 estimate the frequency offset amount using signals received by a plurality of receiving modules in order to increase noise resistance. As a result, since the number of samples to be averaged increases, noise immunity increases, and the frequency offset amount can be estimated more accurately. As a result, by compensating the frequency offset using the offset amount obtained by the automatic frequency controllers 801 and 851, the frequency offset amount remaining after the frequency offset is compensated by the automatic frequency controller can be reduced.
Other processes are the same as those in the first embodiment, and the function of the wireless reception device can be expanded using a plurality of reception modules as in the first embodiment.

  As described above, according to the present embodiment, in addition to the effects of the first embodiment, the frequency offset amount is estimated using signals received by a plurality of receiving modules, so that the frequency offset amount estimation accuracy is increased and the accuracy is improved. High frequency offset compensation can be realized.

(Sixth embodiment)
A radio reception apparatus according to the sixth embodiment of the present invention will be described with reference to FIG.
Also in this embodiment, two receiving modules are used. In this embodiment, the same points as in the fourth embodiment are that the channel response estimated by the channel estimating unit and the phase correction by the phase corrector are performed. A point having an interface for outputting the latter signal to the outside, a propagation path response estimated value estimated by the external receiving module, and a signal whose phase has been corrected by the external receiving module; a MIMO reception weight calculation unit and a MIMO demodulator; And an interface for outputting the frequency offset estimation amount estimated by the automatic frequency controller to the external reception module and an interface for setting the frequency offset amount from the outside. It is a point that has the function of correcting the frequency offset based on the set value

  This embodiment is different from the fourth embodiment in that each receiving module outputs an interface that outputs the phase error amount estimated by the phase corrector to the external receiving module, and the phase error amount from the external receiving module. The phase corrector of each receiving module has a function of compensating for the phase error, and each receiving module is multiplied by the inverse characteristic of the same phase error amount.

  As described in the first and fourth embodiments, a local frequency error occurs between the transmitter and the receiver in wireless communication, and the frequency offset amount cannot be accurately estimated by the automatic frequency controller. In some cases, the frequency offset remains in the output of the automatic frequency controller. In addition to the frequency offset, it is necessary to compensate for the phase error due to phase noise that has time variation and the phase corrector of this embodiment estimates the phase error by observing the phase variation of the pilot signal. Then, the phase error is corrected by multiplying the reception signal by the inverse characteristic.

  Therefore, in the present embodiment, the phase error is estimated using the phase corrector 901 or 951 of one of the receiving modules, the estimated phase error amount is transmitted to the other receiving modules, and the phase corrector in each receiving module is This phase error amount is used to compensate for the phase error. As a result, the phase error amount remaining after the phase error is compensated by the phase corrector becomes the same in each receiving module, and signal separation can be performed by the MIMO demodulator.

  As described above, according to the present embodiment, in addition to the effects of the first embodiment, the phase error amount remaining in each receiving module is the same, so that it is possible to prevent deterioration in signal separation of the MIMO demodulator.

(Seventh embodiment)
A radio reception apparatus according to the seventh embodiment of the present invention will be described with reference to FIG.
In this embodiment, two receiving modules are used, and the same points as in the sixth embodiment in this embodiment are that the channel response estimated by the channel estimation unit and the phase correction by the phase corrector are performed. A point having an interface for outputting the latter signal to the outside, a propagation path response estimated value estimated by the external receiving module, and a signal whose phase has been corrected by the external receiving module; a MIMO reception weight calculation unit and a MIMO demodulator; And an interface for outputting the frequency offset estimation amount estimated by the automatic frequency controller to the external reception module, and an interface for setting the frequency offset amount from the outside. Point, a point with a function to correct the frequency offset based on the set value, each The interface that outputs the phase error amount estimated by the phase corrector to the external receiver module and the phase error amount from the external receiver module are input, and the phase error is compensated by the phase corrector of each receiver module. It has a function, and each receiving module is multiplied by the inverse characteristic of the same phase error amount.

  This embodiment is different from the sixth embodiment in that each receiving module outputs an FFT signal to an external receiving module, and an interface that inputs an FFT converted signal from the external receiving module. The phase error is estimated by a phase corrector using signals received by a plurality of receiving modules.

  As explained in the sixth embodiment, when a common clock is supplied to each receiving module and the frequency offset amount is corrected by the automatic frequency controller using the same frequency offset amount estimation, it is added to the received signal. The phase error is the same for each receiving module. Therefore, if the phase error is estimated by the phase corrector in one of the receiving modules, and each receiving module compensates the phase error based on this estimated value, the residual phase error after phase correction in all the receiving modules becomes constant. Further, it is possible to prevent distortion that makes signal separation difficult when performing signal separation with a MIMO demodulator.

However, if the phase error is large, the signal separation in the MIMO demodulator is not adversely affected, but the signal point after the separation is rotated according to the phase error. Therefore, it is necessary to estimate the phase error with high accuracy.
Therefore, in this embodiment, the phase error is estimated using signals received by a plurality of receiving modules. Therefore, the signal after FFT of the receiving module 1 1000 is input to the phase corrector 1051 of the receiving module 2 1050, and the signal after FFT of the receiving module 2 is input to the phase corrector 1001 of the receiving module 1. As a result, the signals received by all the receiving modules are input to the phase correctors of each receiving module, and the signals received by all the receiving modules of the autocorrelation or cross-correlation of Equation (3) in the phase corrector. The effect of noise can be reduced by adding using.

  As a result, the phase error amount remaining after the phase error is compensated by the phase corrector becomes the same in each receiving module, and signal separation can be performed by the MIMO demodulator. In addition, since the phase error is estimated using the reception signals of all the reception modules, it is possible to improve the phase error compensation accuracy.

  As described above, according to the present embodiment, in addition to the effects of the first embodiment, phase error compensation is performed using signals received by a plurality of reception modules, so that the phase error compensation accuracy is increased and each reception module is provided. Since the remaining phase error amount becomes the same, deterioration in signal separation of the MIMO demodulator can be prevented.

(Eighth embodiment)
A radio reception apparatus according to the eighth embodiment of the present invention will be described with reference to FIG.
In this embodiment, two receiving modules are used, and the same points as in the first embodiment in this embodiment are that the channel response estimated by the channel estimating unit and the phase correction by the phase corrector are performed. A point having an interface for outputting the latter signal to the outside, a propagation path response estimated value estimated by the external receiving module, and a signal whose phase has been corrected by the external receiving module; a MIMO reception weight calculation unit and a MIMO demodulator; It is a point which has an interface which inputs to each.

  This embodiment is different from the first embodiment in that, for example, the MIMO demodulator 1101 in the reception module 1 1100 outputs the first signal and the second signal, and the first output is the decoding of the reception module 1 1100. The second output is transmitted to the decoder 163 of the receiving module 2 1150, and the signal is decoded using the decoders 113 and 163 included in the receiving module 1 and the receiving module 2, respectively. The signal decoded in step S1 is input to the signal combiner 1102 of the reception module 1, and the signal converted into the serial signal is output as a decoding result.

In the first to seventh embodiments, the wireless transmission device encodes an information signal with one encoder 1201 as shown in FIG. 12, and the serial-parallel converter 1202 performs serial-parallel conversion on the encoded signal. The description has been made assuming that a spatially multiplexed signal is generated.
However, in the configuration shown in FIG. 12, when the number of signals to be multiplexed increases, it is necessary to increase the speed of decoding processing according to the number of signals to be multiplexed, which may make implementation difficult. On the other hand, as shown in FIG. 13, a transmission method in which an information signal is serial-parallel converted and encoded using a plurality of encoders 1301 and 1302 is also conceivable. In the case of this transmission method, it becomes possible to process the decoders in parallel according to the number of encoders, and each decoder is slower than the case of generating a transmission signal using a single encoder. It can be operated.

  In the present embodiment, a radio reception apparatus when a transmission signal is generated using two encoders 1301 and 1302 as shown in FIG. 13 will be described. Details will be described below with reference to FIGS. 11 and 13.

  In this embodiment, the points similar to the first embodiment are that the result of propagation path estimation performed by the reception module 2 is transmitted to the reception module 1, and the result of propagation path estimation estimated by the reception module 1 is included. The reception weight is calculated by the MIMO reception weight calculation unit 111 in the reception module 1, the signal after the phase correction is applied by the reception module 2 is transmitted to the reception module 1, and the phase correction is performed by this signal and the reception module 1. The signal is used to demultiplex and demodulate the multiplexed signal by the MIMO demodulator 1101 in the receiving module 1, and the detailed description is the same as the description in the first embodiment, and therefore will be omitted.

  However, the MIMO demodulator 1101 in the present embodiment performs an operation (selection) opposite to the signal distribution operation in the signal distribution unit 1303 in FIG. 13, and the signal input from the encoder 1301 is output as the first signal. For the signal input from the encoder 1302, two parallel signals are output as the second signal.

  Thereafter, the first signal is input to the decoder 113 of the receiving module 1, and the second signal is transmitted to the decoder 163 of the receiving module 2 via the interface. At this time, the decoder 113 of the receiving module 1 switches the switch 1103 so that the signal of the MIMO demodulator 1101 of the receiving module 1 is input, and the decoder 163 of the receiving module 2 is the switch 1153 so that the signal from the outside is input. Switch. By performing the control in this way, the information of the signal encoded by the encoder 1301 of FIG. 13 is input to the decoder 113 of the receiving module 1, and the encoder of FIG. 13 is input to the decoder 163 of the receiving module 2. The signals encoded in 1302 are input and can be decoded in parallel. Here, as described in the first embodiment, the decoders 113 and 163 in this embodiment may be either soft decision decoders or hard decision decoders.

  Of the outputs decoded by the two decoders 113 and 163 as described above, the signal decoded by the decoder 163 of the reception module 2 is input to the signal combiner 1102 of the reception module 1 via the interface. The signal decoded by the decoder 113 of the receiving module 1 is also input to the signal combiner 1102 of the receiving module 1. Here, the signal combiner 1102 of the reception module 1 converts the input parallel signal into a serial signal according to a rule reverse to that of the serial / parallel conversion unit 1202 of the wireless transmission device illustrated in FIG. 13. The above signal is output as a reception result for the transmitted information signal.

  At this time, since the MIMO reception weight calculation unit 161, the MIMO demodulator 1151, and the signal combiner 1152 in the reception module 2 are not required to output, the control unit 114 may stop supplying the clock. Thus, by stopping the supply of the clock to the circuit portions that are not necessary, power consumption can be reduced.

  Although the details in the present embodiment have been described as being derived from the first embodiment, the expansion in the present embodiment can be applied to each of the second to seventh embodiments.

  As described above, according to the present embodiment, in addition to the effects of the first embodiment, the number of signals to be multiplexed is increased by operating the decoder included in each receiving module in parallel at the time of decoding. Also, the decoder can be operated at the same speed as before the combination. In addition, it is possible to prevent deterioration in signal separation of the MIMO demodulator by correcting with the same correction amount in the correction of the frequency offset amount, and estimating the frequency offset amount using the signals received by all the receiving modules. Therefore, the estimation accuracy of the offset amount can be improved. Further, by correcting the phase error with a correction amount common to each receiving module, it is possible to prevent degradation of signal separation in the MIMO demodulator, and to estimate the phase error using signals received by all receiving modules. Thus, the estimation accuracy of the phase error can be improved. Furthermore, waste of power consumption can be prevented by stopping unnecessary blocks in the receiving module 2.

  Note that the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. In addition, various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, constituent elements over different embodiments may be appropriately combined.

1 is a block diagram of a wireless reception device according to a first embodiment of the present invention. The figure which shows the frame format of the signal which the radio | wireless receiver of FIG. 1 receives. The figure which shows the propagation path response matrix which the propagation path estimation part of FIG. 1 estimates. The block diagram which shows another example of the radio | wireless receiver of FIG. The block diagram of the radio | wireless receiver which concerns on the 2nd Embodiment of this invention. The block diagram of the radio | wireless receiver which concerns on the 3rd Embodiment of this invention. The block diagram of the radio | wireless receiver which concerns on the 4th Embodiment of this invention. The block diagram of the radio | wireless receiver which concerns on the 5th Embodiment of this invention. The block diagram of the radio | wireless receiver which concerns on the 6th Embodiment of this invention. The block diagram of the radio | wireless receiver which concerns on the 7th Embodiment of this invention. The block diagram of the radio | wireless receiver which concerns on the 8th Embodiment of this invention. The block diagram of the radio | wireless transmitter which transmits the signal which the radio | wireless receiver which concerns on the 1st-7th embodiment of this invention receives. The block diagram of the radio | wireless transmitter which transmits the signal which the radio | wireless receiver which concerns on the 8th Embodiment of this invention receives.

Explanation of symbols

100, 150, 400, 450, 500, 550, 600, 650, 700, 750, 800, 850, 900, 950, 1000, 1050, 1100, 1150... Receiving module, 101, 102, 151, 152. 103, 104, 153, 154 ... A / D converter, 105, 155, 601, 651 ... timing synchronization unit, 106, 156, 701, 751, 801, 851 ... automatic frequency controller, 109, 159 ... propagation path estimation 110, 160, 901, 951, 1001, 1051... Phase corrector, 111, 161... MIMO reception weight calculation unit, 112, 162, 1101, 1151... MIMO demodulator, 113, 163. , 401, 451 ... control unit, 115, 165 ... switch control unit, 116, 1 7, 118, 119, 166, 167, 168, 169, 402, 452, 501, 551, 1103, 1153... Switch, 1102, 1152... Signal combiner, 1201, 1301, 1302. , 1303... Signal distribution unit.

Claims (11)

A plurality of antennas for receiving multiplexed signals;
A plurality of radio units connected one-to-one to the plurality of antennas;
A plurality of analog-digital converters connected to the plurality of radio units in a one-to-one relationship and converting analog signals into digital signals;
Timing calculating means for calculating a timing of applying Fourier transform to each digital signal based on each digital signal;
Connected to the plurality of analog-digital converters, and based on a plurality of digital signals output from the analog-digital converter, an error between the frequency of the transmitter of the received analog signal and the frequency at each radio unit First generation means for correcting a certain frequency offset amount and generating the same number of digital signals as the plurality of radio units;
A plurality of Fourier transform units installed in a one-to-one correspondence with the plurality of radio units, and applying a Fourier transform to the plurality of generated digital signals;
Channel estimation means for estimating a channel response based on the plurality of Fourier-transformed digital signals;
A second generation unit configured to correct an error that has not been corrected by the first generation unit based on the plurality of digital signals that have undergone Fourier transform, and to generate the same number of digital signals as the plurality of radio units;
Weight calculating means for calculating a plurality of weights for separating the multiplexed signal based on the propagation path response;
A first interface connected to another module;
Installed between the propagation path estimation means and the weight calculation means and connected between the propagation path estimation means and the weight calculation means, or connected between the propagation path estimation means and the first interface. A first switch that switches to either one of them;
Separating and demodulating means for separating and demodulating the multiplexed signal received from the second generating means based on the plurality of weights;
A second interface connected to other modules;
Installed between the second generating means and the demultiplexing / demodulating means and connected between the second generating means and the demultiplexing / demodulating means, or connected between the second generating means and the second interface. The same number of second switches as the plurality of radio units, which are switched to one of them;
Decoding means for decoding each of the separately demodulated signals;
A switch control means for controlling switching of each switch, and a first module and a second module, respectively,
The switch control means of the first module controls the first switch of the first module so as to connect the propagation path estimation means of the first module and the weight calculation means of the first module, and the first module Controlling the second switch of the first module so as to connect the second generation means of the first module and the separation and demodulation means of the first module;
The switch control means of the second module calculates the weight calculation means of the first module further based on the propagation path response from the propagation path estimation means of the second module via the first interface of the second module. Controlling the first switch of the second module so that the demultiplexing means of the first module further receives the multiplexed signal received from the second generating means of the second module. Control the second switch of
The weight calculation means of the first module calculates a plurality of weights corresponding to a plurality of signals received by the plurality of antennas of the first module and the second module;
The radio receiving apparatus according to claim 1, wherein the demultiplexing / demodulating means of the first module synthesizes the signals received by the plurality of antennas of the first module and the second module to demultiplex the multiplexed signals. The weight calculation means of the first module calculates a weight for demodulating a signal obtained by multiplexing a plurality of signals received by the plurality of antennas of the first module and the second module,
2. The radio receiving apparatus according to claim 1, wherein the demultiplexing unit of the first module demodulates multiplexed signals received by the plurality of antennas of the first module and the second module. A third interface connected to other modules;
Installed between the timing calculation unit and the plurality of Fourier transform units, and connects the timing calculation unit and the plurality of Fourier transform units, or connects the plurality of Fourier transform units and the third interface. A third switch for switching to one of the states to be
Timing operation control means for controlling whether to stop the operation of the timing calculation means,
The switch control means of the first module controls the third switch of the first module to connect the plurality of Fourier transform units of the first module and the third interface of the first module, and the stop control means The operation of the timing calculation means of the first module is stopped, the switch control means of the second module controls the third switch of the second module, and the first module via the third interface of the first module A plurality of Fourier transform units of the second module and the timing calculation means of the second module,
Alternatively, the switch control means of the first module controls the third switch of the first module to connect the plurality of Fourier transform units of the first module and the timing calculation means of the first module, and the stop control means 3 stops the operation of the timing calculation means of the second module. A fourth interface for connecting the timing calculation means to another module;
The timing calculation means of the first module is connected to a plurality of analog-digital conversion units of the second module via the fourth interface, and based on a plurality of digital signals from the plurality of analog-digital conversion units, The radio reception apparatus according to claim 1, wherein the timing is calculated. A fifth interface for connecting the first generation means and another module;
The first generation unit of the first module is connected to the first generation unit of the second module via the fifth interface, receives a frequency offset amount in the first generation unit of the second module, and receives the frequency The radio reception apparatus according to any one of claims 1 to 4, wherein the digital signal is generated based on an offset amount. A fifth interface for connecting the first generation means and another module;
The first generation means of the first module is connected to a plurality of analog-digital conversion units of the second module via the fifth interface, and also to a plurality of digital signals from the plurality of analog-digital conversion units. The radio reception apparatus according to claim 1, wherein the digital signal is generated based on the radio signal. A sixth interface for connecting the second generation means and another module;
The second generating means of the first module is connected to the second generating means of the second module via the sixth interface, receives the corrected error in the second generating means of the second module; The radio reception apparatus according to claim 1, wherein the digital signal is generated based on an error. A seventh interface for connecting the second generation means and another module;
The second generation unit of the first module is connected to the plurality of Fourier transform units of the second module through the seventh interface, and based on the plurality of digital signals from the plurality of Fourier transform units, The radio reception apparatus according to claim 1, wherein the radio reception apparatus generates a digital signal.   2. The apparatus according to claim 1, further comprising stop control means for stopping operations of the weight calculation means of the second module, the separation / demodulation means of the second module, and the decoding means of the second module. 9. The wireless reception device according to any one of items 8. In the case where the plurality of antennas receive signals encoded by two encoders, the demultiplexing / demodulating means outputs a first demodulated signal and a second demodulated signal corresponding to the two encoders. Select the signal,
An eighth interface connected to other modules;
A state in which the first demodulated signal is output from the separation / demodulation unit to the decoding unit, or a state in which the eighth interface and the decoding unit are connected. A fourth switch to switch to either one of them;
Serial conversion means for converting the decoded signal output from the decoding means of the first module and the decoding means of the second module into a serial signal;
The switch control means of the first module controls the fourth switch of the first module so as to output the first demodulated signal from the demodulating means of the first module to the decoding means of the first module, The switch control means of the second module connects the eighth interface of the second module and the decoding means of the second module, and sends the second demodulated signal from the separation / demodulation means of the first module to the second module. 9. The radio receiving apparatus according to claim 1, wherein the fourth switch of the second module is controlled to output to the decoding means.   11. The apparatus according to claim 10, further comprising a stop control unit that stops operations of the weight calculation unit of the second module, the separation / demodulation unit of the second module, and the serial conversion unit of the second module. Wireless receiver.

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